Hi all,
(skip to the bold bit if you don't want the background information).

My sister manages ski chalets in France, increasingly customers want reliable internet access when on holidays and get grumpy when it does not 'just work' :wink:
She has two chalets buildings each with it's own ADSL line for historical reasons one is with Orange Fr and one is with SFR.

I have found the Orange live box to be dire, the built in DNS resolver falls over and causes web page download failure every few mins. Forcing devices to use external DNS servers fixes this but she can't tell all the guests to do this, it should 'just work'.

A 2nd problem is that the ADSL service in the area can be unreliable and fail, particularly near the beginning and end of season when it snows or melts a lot.

A 3rd problem is the number of internet devices each guest has, in the past family would have a laptop. These days it is not unusual to have 50 guests each with a smartphone, tablet and/or laptop. This is made worse on change-over days when 50 guest leave and 50 new ones arrive. I have already increased the DHCP pool size on the existing routers and would shorten the DHCP lease time if I could find the setting.

I have recommended that she buys a decent router for each chalets building, this would help with the DNS resolver issues. I have used Draytek routers for over a decade (currently using a 2830) so have good experience in setting these up and find them reliable.

It occurred to me that to provide some degree of backup, it should be possible to link the two Draytek routers so that if one ADSL line goes down the traffic could be diverted over to the other.
To me this is not a conventional fail over situation because each router should be able to fail over to the other?

I could configure one router to fail to the other by linking the WAN port of one the LAN port of the other. This would be half the solution.

I could even cross link Router1 WAN -> Router 2 LAN port and Router2 WAN -> Router 1 LAN port. With some careful set-up this would probably work but does not appeal to me on a technical level and needs two 'cables' between the routers in the separate buildings.

The buildings are ~100m apart and I was hoping to avoid wires and use a wireless link between them, something like a pair of 5GHz wireless bridge devices like EnGenius NET-EL-ENH500. I would not use the built in 2.4G WiFi on the routers for two reasons, the routers are in the basement surrounded by think walls and the local wireless environment is stuffed full of 2.4GHz WiFi signals!

In an ideal world I would buy two 2830, one for each building, set them each to provide NAT, DHCP and DNS to their local subnet (say 192.168.1.x and 192.168.2.x) and then connect the two WAN ports over a separate wireless bridge using EnGenius NET-EL-ENH500 units but I can't think how to configure them to fail over to each other.

Any thoughts or suggestions welcome

Regards, Mark Leman

Hi not replying about the last bolt question (sorry) but to main 1 & 2 issues if will hep you in future (assuming you have 28... or 29... sereis)
1-
Find with a tool for 3rd part dns server to see which one is best (usually fasters dns servers) for your 2 connections
Go to >>Lan General Set Up >> Details Page ... and add them there so the router will use them for both connections
Since i have done this my 2850 it fails once a month if that

2-
same issue here when snowed had so much packet loss at monitor and so may errors at draytek
I know is my adsl line and NOT the draytek
How to fix?
Try different modem code STD is ok but the 2471201 is the best.Watching the forum regular i see from other users are reporting less errors with bad lines

Hi babis3g,
Thanks for the comments, I think both 1 and 2 will be solved by using decent routers (hopefully draytek ones and a two way fail over.

for the points I originally listed:

1. The problem is purely due to the rubbish orange live box and it's flaky DNS resolver. When I override it's DNS settings and use external DNS servers (say 8.8.8.8) the broadband works fine. I fully expect this problem to go away with a decent router.

2. My aim here in linking the two sites is to reduce the risk of down time due to the line. It is inevitable that when the snow all melts an everything gets very wet the phone lines will play up, hopefully by having two sites which are separated by a few 100m the phone lines will go via different junction boxes/cables etc and the chance of both failing at the same time is less likely. Hence my desire to do two way fail over between to routers.

Regards, Mark Leman

I have found some one asking how to solve exactly the same problem on a CISCO forum:

https://supportforums.cisco.com/thread/2173033

Will have to see if any of the methods suggested are applicable to Draytek routers.

Regards, Mark Leman